Many downtown drivers are furious right now about the closing of Congress Street. Cars have been temporarily banned while tracks are being laid for the streetcar.

It may be a moment unprecedented in Tucson's modern history: For a few months, the needs of public transit have priority over the needs of automobiles. For a few months, in one small corner of the city, the car is not king.

Which makes this a perfect time for Bill Mackey's Worker Transit Authority evenings. A series of events that are part art installation, part spoof and part deadly serious about the way cars shape American cities, Worker Transit Authority will run every Friday and Saturday night for the next three weeks.

"The purpose is to bring (planning) to the forefront," says Mackey, an architect with his own practice who also teaches at the UA. "This is our world. This is what makes our life. Pay attention, folks."

Installed in a vacant building downtown—it once housed a charter school—the show will feature videos, maps, sculptures, interactive activities and questionnaires, all designed to generate discussions about "land use, infrastructure, transportation and the environment," Mackey says.

As earnest as Mackey is about getting people to look at their use of cars, he mostly wants visitors to have fun.

"The W.T.A. is a mock planning organization, and the show has whimsy," he says. "I try to make the point through humor."

The exhibition is full of goofy conceptual drawings—like a map showing the location of each and every one of Tucson's 72 Circle K's. (Intern Jeffrey Buesing, a UA student, gets credit for the tedious task.)

In Mackey's imaginary Consumer Transit System—which has a special route for every store chain—the public Circle K "bus" would be a Chevette with a Coke dispenser on top.

Tucson's heavily traveled Target route would be served by five linked buses, and the tonier Whole Foods would get a six-door Prius. Pushing the parody into the realm of the surreal, Mackey printed up all of these fake routes into official-looking transit maps, and created sophisticated parody renderings of his imaginary vehicles.

Visitors to the free W.T.A. evenings will be handed a blank map of Tucson and a set of colored markers. With those eye-opening Circle K routes fresh in their minds, visitors will sketch in their own life routes: How far do they drive to work? How far do they drive to shop?

They can also fill out questionnaires about their habits, and sign up for fake committees in a fake W.T.A. public-planning process. W.T.A. exists only in Mackey's fertile brain but—who knows?—the data he gathers may have a shot at influencing city policy if he accumulates enough information.

"Maybe this will turn into a real thing," he muses.

Exhibits include continuously looping videos made by the hard-working Buesing, charting his own journeys from his foothills home to La Encantada, by car, by bicycle and on foot.

"You hear the sounds of gravel and the birds when he's walking. And the wind and the radio when he's in the car," Mackey says. "You're watching (Buesing) doing what you do all the time."

Another section imagines a bicycle-dominant city. Artists Dwight Metzger and Ben Olmstead created traffic signs and tiny billboards geared toward low-slung bicyclists. The signs range from the polite "Share the Shoulder" to the furious "Developers: Go Build in Hell."

"If the world was filled with bikes," Mackey says, "this is how we'd advertise."

A set of overlay maps by Mackey are startling. In one, Hong Kong lies atop the city of Tucson. The Asian city occupies a much smaller land mass than our desert burg, but, astonishingly, Hong Kong packs in 7 million people to Tucson's 1 million. And, not so incidentally, Mackey notes, Hong Kong has the only transit system in the world that runs at a profit.

Mackey and his wife, Rachel Yaseen, former owners of what was downtown's Monkey Box restaurant, don't own a car. They do rent one if they're traveling out of town, but they cruise around their central neighborhood in a golf cart, and when they take their 5-year-old son, Wexler, to his kindergarten, they walk.

Originally from the Chicago suburb of Lake Forest, Mackey came to Tucson to study architecture at the UA. He worked at a number of local architectural firms, including Burns Wald-Hopkins Shambach Architects; Ibarra Rosano Design Architects; and Rob Paulus Architect before opening his own practice, Worker, Inc.

"I'm interested in the built environment," he says, sitting in the downtown space where he's staging W.T.A. "Everything I've done for the last three years is related to transit. Cars are so pervasive."

Gesturing toward Broadway Boulevard and the buildings across the street, he says, "Every single piece of the built environment outside this window is because of a car. As an architect, you see that all the time."

A few years back, Mackey exhibited architecture-inspired collages in visual-art exhibitions at Dinnerware and MOCA. But he began to believe that "drawing a pretty picture is the last thing you need to do." He started staging multigenre exhibitions that asked pointed questions about space and place, and combined art and city planning.

Downtown Master Plans examined no fewer than 169 real-life plans that have been drawn up for Tucson, including one that dated all the way back to 1931. ("They all said the same thing: more trees, and bigger sidewalks.") You Are Here showcased his UA students' perceptions of downtown; Food Paper Alcohol inaugurated the UA space in the old Walgreens building downtown.

"Visual art sits on the wall. With these exhibitions, I try to do more engaging with the audience," he says.

Armed with a P.L.A.C.E. grant from the Tucson Pima Arts Council and the Kresge Foundation, Mackey created his Worker Transit Authority, a project that he admits is "not so neutral as my previous shows."

And in it, he can't resist some provocative humor. With motorists already fuming over the streetcar construction, Mackey created a map that positions all of Tucson's monster malls along the new streetcar route—"as a joke."

The Tucson Mall, drawn in outline, takes up all of downtown north of Congress; Park Place Mall occupies the south. Foothills Mall crushes Fourth Avenue; El Con Mall demolishes West University. And La Encantada alights on the sacred ground of the lost Convento, west of downtown, at the end of the streetcar line.

When people see the mall maps, Mackey chuckles, they ask, "Is this guy serious?"

Mackey doesn't really plan to level the city center, but he does want to get people thinking about how we use our land. Those monster malls, temples to consumption and sprawl, are—amazingly—as big as some of the city's most-cherished districts.

The show is a chance "for people to get together to talk about issues they don't normally talk about, but are an important part of our lives," Mackey says. "It's our choice to decide how we move through the city. What trade-offs do you make? What excuses do you make for your choices? Our individual actions have a really large impact."